package scrapeconfig

import (
	"fmt"
	"reflect"
	"time"

	"github.com/prometheus/common/model"
	"github.com/prometheus/prometheus/discovery"
	"github.com/prometheus/prometheus/discovery/azure"
	"github.com/prometheus/prometheus/discovery/consul"
	"github.com/prometheus/prometheus/discovery/digitalocean"
	"github.com/prometheus/prometheus/discovery/dns"
	"github.com/prometheus/prometheus/discovery/dockerswarm"
	"github.com/prometheus/prometheus/discovery/ec2"
	"github.com/prometheus/prometheus/discovery/file"
	"github.com/prometheus/prometheus/discovery/gce"
	"github.com/prometheus/prometheus/discovery/kubernetes"
	"github.com/prometheus/prometheus/discovery/marathon"
	"github.com/prometheus/prometheus/discovery/openstack"
	"github.com/prometheus/prometheus/discovery/triton"
	"github.com/prometheus/prometheus/discovery/zookeeper"
	"github.com/prometheus/prometheus/pkg/relabel"
	"github.com/weaveworks/common/server"

	"github.com/grafana/loki/pkg/logentry/stages"
)

// Config describes a job to scrape.
type Config struct {
	JobName                string                 `yaml:"job_name,omitempty"`
	PipelineStages         stages.PipelineStages  `yaml:"pipeline_stages,omitempty"`
	JournalConfig          *JournalTargetConfig   `yaml:"journal,omitempty"`
	SyslogConfig           *SyslogTargetConfig    `yaml:"syslog,omitempty"`
	PushConfig             *PushTargetConfig      `yaml:"loki_push_api,omitempty"`
	RelabelConfigs         []*relabel.Config      `yaml:"relabel_configs,omitempty"`
	ServiceDiscoveryConfig ServiceDiscoveryConfig `yaml:",inline"`
}

type ServiceDiscoveryConfig struct {
	// List of labeled target groups for this job.
	StaticConfigs discovery.StaticConfig `yaml:"static_configs"`
	// List of DNS service discovery configurations.
	DNSSDConfigs []*dns.SDConfig `yaml:"dns_sd_configs,omitempty"`
	// List of file service discovery configurations.
	FileSDConfigs []*file.SDConfig `yaml:"file_sd_configs,omitempty"`
	// List of Consul service discovery configurations.
	ConsulSDConfigs []*consul.SDConfig `yaml:"consul_sd_configs,omitempty"`
	// List of DigitalOcean service discovery configurations.
	DigitalOceanSDConfigs []*digitalocean.SDConfig `yaml:"digitalocean_sd_configs,omitempty"`
	// List of Docker Swarm service discovery configurations.
	DockerSwarmSDConfigs []*dockerswarm.SDConfig `yaml:"dockerswarm_sd_configs,omitempty"`
	// List of Serverset service discovery configurations.
	ServersetSDConfigs []*zookeeper.ServersetSDConfig `yaml:"serverset_sd_configs,omitempty"`
	// NerveSDConfigs is a list of Nerve service discovery configurations.
	NerveSDConfigs []*zookeeper.NerveSDConfig `yaml:"nerve_sd_configs,omitempty"`
	// MarathonSDConfigs is a list of Marathon service discovery configurations.
	MarathonSDConfigs []*marathon.SDConfig `yaml:"marathon_sd_configs,omitempty"`
	// List of Kubernetes service discovery configurations.
	KubernetesSDConfigs []*kubernetes.SDConfig `yaml:"kubernetes_sd_configs,omitempty"`
	// List of GCE service discovery configurations.
	GCESDConfigs []*gce.SDConfig `yaml:"gce_sd_configs,omitempty"`
	// List of EC2 service discovery configurations.
	EC2SDConfigs []*ec2.SDConfig `yaml:"ec2_sd_configs,omitempty"`
	// List of OpenStack service discovery configurations.
	OpenstackSDConfigs []*openstack.SDConfig `yaml:"openstack_sd_configs,omitempty"`
	// List of Azure service discovery configurations.
	AzureSDConfigs []*azure.SDConfig `yaml:"azure_sd_configs,omitempty"`
	// List of Triton service discovery configurations.
	TritonSDConfigs []*triton.SDConfig `yaml:"triton_sd_configs,omitempty"`
}

func (cfg ServiceDiscoveryConfig) Configs() (res discovery.Configs) {
	if x := cfg.StaticConfigs; len(x) > 0 {
		res = append(res, x)
	}
	for _, x := range cfg.DNSSDConfigs {
		res = append(res, x)
	}
	for _, x := range cfg.FileSDConfigs {
		res = append(res, x)
	}
	for _, x := range cfg.ConsulSDConfigs {
		res = append(res, x)
	}
	for _, x := range cfg.DigitalOceanSDConfigs {
		res = append(res, x)
	}
	for _, x := range cfg.DockerSwarmSDConfigs {
		res = append(res, x)
	}
	for _, x := range cfg.ServersetSDConfigs {
		res = append(res, x)
	}
	for _, x := range cfg.NerveSDConfigs {
		res = append(res, x)
	}
	for _, x := range cfg.MarathonSDConfigs {
		res = append(res, x)
	}
	for _, x := range cfg.KubernetesSDConfigs {
		res = append(res, x)
	}
	for _, x := range cfg.GCESDConfigs {
		res = append(res, x)
	}
	for _, x := range cfg.EC2SDConfigs {
		res = append(res, x)
	}
	for _, x := range cfg.OpenstackSDConfigs {
		res = append(res, x)
	}
	for _, x := range cfg.AzureSDConfigs {
		res = append(res, x)
	}
	for _, x := range cfg.TritonSDConfigs {
		res = append(res, x)
	}
	return res
}

// JournalTargetConfig describes systemd journal records to scrape.
type JournalTargetConfig struct {
	// MaxAge determines the oldest relative time from process start that will
	// be read and sent to Loki. Values like 14h means no entry older than
	// 14h will be read. If unspecified, defaults to 7h.
	//
	// A relative time specified here takes precedence over the saved position;
	// if the cursor is older than the MaxAge value, it will not be used.
	MaxAge string `yaml:"max_age"`

	// JSON forces the output message of entries read from the journal to be
	// JSON. The message will contain all original fields from the source
	// journal entry.
	JSON bool `yaml:"json"`

	// Labels optionally holds labels to associate with each record coming out
	// of the journal.
	Labels model.LabelSet `yaml:"labels"`

	// Path to a directory to read journal entries from. Defaults to system path
	// if empty.
	Path string `yaml:"path"`
}

// SyslogTargetConfig describes a scrape config that listens for log lines over syslog.
type SyslogTargetConfig struct {
	// ListenAddress is the address to listen on for syslog messages.
	ListenAddress string `yaml:"listen_address"`

	// IdleTimeout is the idle timeout for tcp connections.
	IdleTimeout time.Duration `yaml:"idle_timeout"`

	// LabelStructuredData sets if the structured data part of a syslog message
	// is translated to a label.
	// [example@99999 test="yes"] => {__syslog_message_sd_example_99999_test="yes"}
	LabelStructuredData bool `yaml:"label_structured_data"`

	// Labels optionally holds labels to associate with each record read from syslog.
	Labels model.LabelSet `yaml:"labels"`

	// UseIncomingTimestamp sets the timestamp to the incoming syslog mesages
	// timestamp if it's set.
	UseIncomingTimestamp bool `yaml:"use_incoming_timestamp"`
}

// PushTargetConfig describes a scrape config that listens for Loki push messages.
type PushTargetConfig struct {
	// Server is the weaveworks server config for listening connections
	Server server.Config `yaml:"server"`

	// Labels optionally holds labels to associate with each record received on the push api.
	Labels model.LabelSet `yaml:"labels"`

	// If promtail should maintain the incoming log timestamp or replace it with the current time.
	KeepTimestamp bool `yaml:"use_incoming_timestamp"`
}

// DefaultScrapeConfig is the default Config.
var DefaultScrapeConfig = Config{
	PipelineStages: []interface{}{
		map[interface{}]interface{}{
			stages.StageTypeDocker: nil,
		},
	},
}

// HasServiceDiscoveryConfig checks to see if the service discovery used for
// file targets is non-zero.
func (c *Config) HasServiceDiscoveryConfig() bool {
	return !reflect.DeepEqual(c.ServiceDiscoveryConfig, ServiceDiscoveryConfig{})
}

// UnmarshalYAML implements the yaml.Unmarshaler interface.
func (c *Config) UnmarshalYAML(unmarshal func(interface{}) error) error {

	*c = DefaultScrapeConfig

	type plain Config
	if err := unmarshal((*plain)(c)); err != nil {
		return err
	}

	if len(c.JobName) == 0 {
		return fmt.Errorf("job_name is empty")
	}

	return nil
}
